Manufacturing Processes for Engineering Materials, 4th ed.Kalpakjian • SchmidPrentice Hall, 2003

Types Of Extrusion

FIGURE 6.49 Types ofextrusion. (a) direct; (b)indirect; (c) hydrostatic;(d) impact.

Manufacturing Processes for Engineering Materials, 4th ed.Kalpakjian • SchmidPrentice Hall, 2003

Extrusion of Seamless Tube

FIGURE 6.60 Extrusion of a seamless tube. The hole in the billet may be prepunched orpierced, or it may be generated during extrusion.;

Manufacturing Processes for Engineering Materials, 4th ed.Kalpakjian • SchmidPrentice Hall, 2003

Cold and Impact Extrusion

FIGURE 6.56 Examples of coldextrusion. Arrows indicate thedirection of material flow. Theseparts may also be considered asforgings.

FIGURE 6.57 (a) Impact extrusion of acollapsible tube (Hooker process).(b) Twoexamples of products made by impactextrusion, these parts may also be madeby casting, forging, and machining,depending on the dimensions andmaterials involved and the propertiesdesired. Economic considerations are alsoimportant in final process selection.

Kalpakjian • SchmidManufacturing Engineering and Technology © 2001 Prentice-Hall Page 15-14

Cold Extruded Spark Plug

Figure 15.12 Production steps for a cold extrudedspark plug. Source: National Machinery Company.

Figure 15.13 A cross-section of the metal partin Fig. 15.12, showing the grain flow pattern.Source: National Machinery Company.

AME 50542: Manufacturing Processes for Engineering Materials (R.K. Roeder)

Clay Drainage Tile

Water

Ditch

Clay Drainage TilesCross-Sectionof the Earth

• In agricultural drainage systems many clay tiles remain in use after up to 100 years.

• New drainage systems use corrugated PVC piping.

AME 50542: Manufacturing Processes for Engineering Materials (R.K. Roeder)

Clay Drainage Tile Manufacturing• Earliest drainage tile shaped on a potter's wheel (4000 BC).

• The first American mass production was in 1875 (New Jersey), reaching Indiana by 1885.

Adapted from: H.C. Plummer, Brick and Tile Engineering Handbook of Design,Structural Clay Products Institute, Washington, DC, 1950.

AME 50542: Manufacturing Processes for Engineering Materials (R.K. Roeder)

Clay Drainage Tile Manufacturing

Adapted from: H.C. Plummer, Brick and Tile Engineering Handbook of Design,Structural Clay Products Institute, Washington, DC, 1950.

• Shapes formed by "stiff-mud" extrusion.

AME 50542: Manufacturing Processes for Engineering Materials (R.K. Roeder)

W.F. Hosford and R.M. Caddell, Metal Forming, 2nd Ed., Prentice-Hall, Inc., Edgewood Cliffs, NJ, 1993.

Extrusion

Effects of die angle (α) and contact length (L) on cold extrusion deformation.

Kalpakjian • SchmidManufacturing Engineering and Technology © 2001 Prentice-Hall Page 15-8

Types of Metal Flow in Extruding With SquareDies

Figure 15.7 Types of metal flow in extruding with square dies. (a) Flow pattern obtained at lowfriction, or in indirect extrusion. (b) Pattern obtained with high friction at the billet-chamber interfaces.(c) Pattern obtained at high friction, or with cooling of the outer regions of the billet in the chamber.This type of pattern, observed in metals whose strength increases rapidly with decreasing temperature,leads to a defect known as pipe, or extrusion defect.

Manufacturing Processes for Engineering Materials, 4th ed.Kalpakjian • SchmidPrentice Hall, 2003

Chevron Cracking

FIGURE 6.59 (a) Deformation zone in extrusion, showing rigid and plastic zones. Notethat the plastic zones do not meet, leading to chevron cracking. The same observations arealso made in drawing round bars through conical dies and drawing flat sheet plate throughwedge-shaped dies. Source: After B. Avizur. (b) Chevron cracking in round steel barsduring extrusion. Unless the part is inspected properly, such internal detects may remainundetected and possibly cause failure of the part in service.

Manufacturing Processes for Engineering Materials, 4th ed.Kalpakjian • SchmidPrentice Hall, 2003

Drawing

FIGURE 6.62 Variables indrawing round rod or wire.

FIGURE 6.63 Variation in strain andflow stress in the deformation zone indrawing. Note that the strain increasesrapidly toward the exit. The reason isthat when the exit diameter is zero, thetrue strain reaches infinity. The pointYwire represents the yield stress of thewire.

Manufacturing Processes for Engineering Materials, 4th ed.Kalpakjian • SchmidPrentice Hall, 2003

Tube Drawing

FIGURE 6.67 Various methods of tube drawing.

Manufacturing Processes for Engineering Materials, 4th ed.Kalpakjian • SchmidPrentice Hall, 2003

Drawing Dies

FIGURE 6.69 Terminology for atypical die for drawing round rod orwire.

FIGURE 6.70 Schematic illustration ofa typical wear pattern in a wire-drawingdie.